Cradle of Strength

{t} add x {g} to your mana pool, where x is your devotion to green
{g}{t} add a growth counter to Cradle of Strength
Whenever a creature enters the battlefield, you may remove any number of growth counters from Cradle of Strength, and put a +1/+1 counter onto that creature for every growth counter removed this way.
"Nature doesn't always stand idly by."-Gronill the Druid